Hydraulic Modulator Circuit Operation

CIRCUIT OPERATION
The hydraulic modulator is used for controlling the brake system pressure to the wheels. The modulator is composed of four solenoids.

Circuits involved are: B142 for the left front wheel, B143 for the right front wheel, B146 for the left rear wheel, and B148 for the right rear wheel.

The solenoids use a common ground on the Z1 circuit. There are two Z1 circuits from the modulator.

Both of these grounds terminate at the right frame rail, and are spliced in with the ABS pump motor and the ABS system relay.